[PATCH net-next 07/12] net: dsa: rzn1-a5psw: add statistics support

["Clément Léger" <clement.leger@bootlin.com>]

Add per-port statistics. This support requries to add a stat lock since
statistics are stored in two 32 bits registers, the hi part one being
global and latched when accessing the lo part.

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
---
 drivers/net/dsa/rzn1_a5psw.c | 101 +++++++++++++++++++++++++++++++++++
 drivers/net/dsa/rzn1_a5psw.h |   2 +
 2 files changed, 103 insertions(+)

diff --git a/drivers/net/dsa/rzn1_a5psw.c b/drivers/net/dsa/rzn1_a5psw.c
index 5bee999f7050..7ab7d9054427 100644
--- a/drivers/net/dsa/rzn1_a5psw.c
+++ b/drivers/net/dsa/rzn1_a5psw.c
@@ -16,6 +16,59 @@
 
 #include "rzn1_a5psw.h"
 
+struct a5psw_stats {
+	u16 offset;
+	const char *name;
+};
+
+#define STAT_DESC(_offset, _name) {.offset = _offset, .name = _name}
+
+static const struct a5psw_stats a5psw_stats[] = {
+	STAT_DESC(0x868, "aFrameTransmitted"),
+	STAT_DESC(0x86C, "aFrameReceived"),
+	STAT_DESC(0x870, "aFrameCheckSequenceErrors"),
+	STAT_DESC(0x874, "aAlignmentErrors"),
+	STAT_DESC(0x878, "aOctetsTransmitted"),
+	STAT_DESC(0x87C, "aOctetsReceived"),
+	STAT_DESC(0x880, "aTxPAUSEMACCtrlFrames"),
+	STAT_DESC(0x884, "aRxPAUSEMACCtrlFrames"),
+	/* If */
+	STAT_DESC(0x888, "ifInErrors"),
+	STAT_DESC(0x88C, "ifOutErrors"),
+	STAT_DESC(0x890, "ifInUcastPkts"),
+	STAT_DESC(0x894, "ifInMulticastPkts"),
+	STAT_DESC(0x898, "ifInBroadcastPkts"),
+	STAT_DESC(0x89C, "ifOutDiscards"),
+	STAT_DESC(0x8A0, "ifOutUcastPkts"),
+	STAT_DESC(0x8A4, "ifOutMulticastPkts"),
+	STAT_DESC(0x8A8, "ifOutBroadcastPkts"),
+	/* Ether */
+	STAT_DESC(0x8AC, "etherStatsDropEvents"),
+	STAT_DESC(0x8B0, "etherStatsOctets"),
+	STAT_DESC(0x8B4, "etherStatsPkts"),
+	STAT_DESC(0x8B8, "etherStatsUndersizePkts"),
+	STAT_DESC(0x8BC, "etherStatsetherStatsOversizePktsDropEvents"),
+	STAT_DESC(0x8C0, "etherStatsPkts64Octets"),
+	STAT_DESC(0x8C4, "etherStatsPkts65to127Octets"),
+	STAT_DESC(0x8C8, "etherStatsPkts128to255Octets"),
+	STAT_DESC(0x8CC, "etherStatsPkts256to511Octets"),
+	STAT_DESC(0x8D0, "etherStatsPkts512to1023Octets"),
+	STAT_DESC(0x8D4, "etherStatsPkts1024to1518Octets"),
+	STAT_DESC(0x8D8, "etherStatsPkts1519toXOctets"),
+	STAT_DESC(0x8DC, "etherStatsJabbers"),
+	STAT_DESC(0x8E0, "etherStatsFragments"),
+
+	STAT_DESC(0x8E8, "VLANReceived"),
+	STAT_DESC(0x8EC, "VLANTransmitted"),
+
+	STAT_DESC(0x910, "aDeferred"),
+	STAT_DESC(0x914, "aMultipleCollisions"),
+	STAT_DESC(0x918, "aSingleCollisions"),
+	STAT_DESC(0x91C, "aLateCollisions"),
+	STAT_DESC(0x920, "aExcessiveCollisions"),
+	STAT_DESC(0x924, "aCarrierSenseErrors"),
+};
+
 static void a5psw_reg_writel(struct a5psw *a5psw, int offset, u32 value)
 {
 	writel(value, a5psw->base + offset);
@@ -316,6 +369,50 @@ static void a5psw_port_fast_age(struct dsa_switch *ds, int port)
 	a5psw_port_fdb_flush(a5psw, port);
 }
 
+static void a5psw_get_strings(struct dsa_switch *ds, int port, u32 stringset,
+			      uint8_t *data)
+{
+	unsigned int u;
+
+	if (stringset != ETH_SS_STATS)
+		return;
+
+	for (u = 0; u < ARRAY_SIZE(a5psw_stats); u++) {
+		strncpy(data + u * ETH_GSTRING_LEN, a5psw_stats[u].name,
+			ETH_GSTRING_LEN);
+	}
+}
+
+static void a5psw_get_ethtool_stats(struct dsa_switch *ds, int port,
+				    uint64_t *data)
+{
+	struct a5psw *a5psw = ds->priv;
+	u32 reg_lo, reg_hi;
+	unsigned int u;
+
+	for (u = 0; u < ARRAY_SIZE(a5psw_stats); u++) {
+		/* A5PSW_STATS_HIWORD is global and thus, access must be
+		 * exclusive
+		 */
+		spin_lock(&a5psw->stats_lock);
+		reg_lo = a5psw_reg_readl(a5psw, a5psw_stats[u].offset +
+					 A5PSW_PORT_OFFSET(port));
+		/* A5PSW_STATS_HIWORD is latched on stat read */
+		reg_hi = a5psw_reg_readl(a5psw, A5PSW_STATS_HIWORD);
+
+		data[u] = ((u64)reg_hi << 32) | reg_lo;
+		spin_unlock(&a5psw->stats_lock);
+	}
+}
+
+static int a5psw_get_sset_count(struct dsa_switch *ds, int port, int sset)
+{
+	if (sset != ETH_SS_STATS)
+		return 0;
+
+	return ARRAY_SIZE(a5psw_stats);
+}
+
 static int a5psw_setup(struct dsa_switch *ds)
 {
 	struct a5psw *a5psw = ds->priv;
@@ -395,6 +492,9 @@ const struct dsa_switch_ops a5psw_switch_ops = {
 	.phylink_mac_link_up = a5psw_phylink_mac_link_up,
 	.port_change_mtu = a5psw_port_change_mtu,
 	.port_max_mtu = a5psw_port_max_mtu,
+	.get_sset_count = a5psw_get_sset_count,
+	.get_strings = a5psw_get_strings,
+	.get_ethtool_stats = a5psw_get_ethtool_stats,
 	.set_ageing_time = a5psw_set_ageing_time,
 	.port_bridge_join = a5psw_port_bridge_join,
 	.port_bridge_leave = a5psw_port_bridge_leave,
@@ -580,6 +680,7 @@ static int a5psw_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	a5psw->dev = dev;
+	spin_lock_init(&a5psw->stats_lock);
 	spin_lock_init(&a5psw->lk_lock);
 	spin_lock_init(&a5psw->reg_lock);
 	a5psw->base = devm_platform_ioremap_resource(pdev, 0);
diff --git a/drivers/net/dsa/rzn1_a5psw.h b/drivers/net/dsa/rzn1_a5psw.h
index 2d96a2afbc3a..b34ea549e936 100644
--- a/drivers/net/dsa/rzn1_a5psw.h
+++ b/drivers/net/dsa/rzn1_a5psw.h
@@ -177,6 +177,7 @@
  * @mdio_freq: MDIO bus frequency requested
  * @pcs: Array of PCS connected to the switch ports (not for the CPU)
  * @ds: DSA switch struct
+ * @stats_lock: lock to access statistics (shared HI counter)
  * @lk_lock: Lock for the lookup table
  * @reg_lock: Lock for register read-modify-write operation
  * @flooding_ports: List of ports that should be flooded
@@ -190,6 +191,7 @@ struct a5psw {
 	u32 mdio_freq;
 	struct phylink_pcs *pcs[A5PSW_PORTS_NUM - 1];
 	struct dsa_switch ds;
+	spinlock_t stats_lock;
 	spinlock_t lk_lock;
 	spinlock_t reg_lock;
 	u32 flooding_ports;
-- 
2.34.1